MERCon - 2015
Permanent URI for this collectionhttp://192.248.9.226/handle/123/14696
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- item: Conference-Abstract
- item: Conference-AbstractThe Effectiveness of a watersoluble synthetic acrylic polymer in enhancing reinforcing action of Silica in Carboxylated Acrylonitrile Butadiene Rubber Latex(2015) Liyanaarachchi, LADA; Liyanage, NMVKCarboxylated acrylonitrile butadiene rubber (XNBR) latex was filled with surface modified precipitated silica. Surface modification of silica was affected in an aqueous medium by reacting with a synthetic polymer (SP) containing both hydrophilic and hydrophobic groups. The effectiveness of SP in enhancing reinforcing action of silica in XNBR latex films was evaluated through investigation of mechanical properties of vulcanized latex films cast from XNBR latex compounds filled with modified silica over a range of 5 to 20 phr loadings. Tear strength, which is an important mechanical property in certain latex based products like gloves, of modified silica filled cast films was found to be improved in comparison with that of unmodified silica filled cast films. Tear properties of cast films were continued to increase within the range of filler loadings investigated. An optimization of tensile strength was observed at 15phr filler loading in films containing modified fillers and it exceeds the tensile strength of unmodified filler added films with same loading. Morphological studies performed by scanning electron microscopy illustrated that a better distribution of modified filler particles within the XNBR matrix has occurred which may be a consequence of the discouragement of filler aggregation with surface modification. Surface modification of silica has improved the reinforcement action on XNBR.
- item: Conference-AbstractSteady state performance variation of domestic refrigerators under different ambient conditions of Sri LankaAnjana, HMK; Nimarshana, PHV; Attalage, RAThere is a non-negligible variation in climatic conditions in different geographical locations of Sri Lanka. Testing the performance under single climatic condition will not reflect the actual performance of a refrigerator at its intended deployment. This research is aimed at studying the performance of a domestic refrigerator unit under simulated climatic conditions representing different climate zones in Sri Lanka with respect to its dry bulb temperature. Experiments were conducted under controlled environmental conditions to emulate the climatic conditions of different climatic zones in Sri Lanka. Average hourly power consumption under each climatic condition was calculated from the results. Projected annual energy consumption and performance of the overall refrigeration cycle were also estimated. Results indicated a 5.6% increase of energy consumption per 1̊C increase of ambient temperature. Annual power consumption shows 54.2% variation within the evaluated locations. A simulation model was developed to perform the evaluation. Existing mathematical model was adopted to calculate the performance of the refrigeration cycle.
- item: Conference-AbstractSimulation of ancient wind-driven iron smelting furnaces of Sri LankaKumbalathara, AAK; Liyanage, DD; Witharana, S; Rajika, JKAT; Narayana, M; Fernando, KCNMetal processing industry in Sri Lanka began around 3000BC. Ancient chronicles like Mahavansaya, Thupavansa and Pujavaliya proved the Sri Lanka’s history of metal industry. Archaeometallurgical surveys of Sri Lanka have revealed a non-conventional wind-driven iron smelting furnace for the first time in the world. Some of them dated back to third century BC. Replications of iron smelting process have shown the ability of those furnaces to operate and produce high carbon Steel. CFD modeling and simulation is a popular tool to further understand the fluid flow patterns within and surrounding a furnace. This paper discusses the initial steps of modeling and simulation of the total process of iron smelting in the west-facing furnaces situated in Samanalawewa area of Sri Lanka. Main focus of the paper is to analyze the cold flow at 2D and 3D steady state conditions by using the open source OpenFOAM CFD software with over 9million cells for 3D simulation in finite volume method. The results have been compared with a validated simulation on the same furnace using the commercial CFD code Fluent.
- item: Conference-AbstractSchema-independent scientific data cataloging frameworkNakandala, S; Withana, SD; Kumarasiri, D; Jayawardena, H; Bandara, HMND; Perera, S; Marru, S; Pamidighantam, SModern scientific experiments generate vast volumes of data which are hard to keep track of. Consequently, scientists find it difficult to reuse and share these data sets. We address this problem by developing a schema-independent data cataloging framework for efficient management of scientific data. The proposed solution consists of an agent which automatically identifies new data products and extract metadata from them, as well as a server which indexes the metadata using a NoSQL database and provides a REST API for querying, sharing, and reusing the data sets. The novelty of our solution lies in the pluggable metadata extraction logic, extensible data product generation monitors, use of a NoSQL database, and the ability to dynamically add new metadata fields. The use of Apache Solr as the backend database enables the proposed solution to index and search data products much fatser than a solution based on relational databases. For example, our Apache Solr based implementation can resolve full text, sub-string, prefix, and suffix queries 91% - 99% faster than a MySQL-based implementation.
- item: Conference-AbstractScheduling methodology to minimize random customer arrivalKothalawala, KDHA; Samarasekera, NAThe main problem addressed by the research is random arrival of customers to pick goods at a product distribution center. Using a Case Study approach, a methodology is developed for scheduling of customer arrivals as a solution. Initially the problem is studied in detail. A survey was carried out to study the current customer behavior of the selected product distribution center. Using the findings of the survey and the literature review, different scheduling solutions are generated. Three most viable solutions are selected and then those three solutions are evaluated in financial, operational and change management aspects to find the best solution. A simulation is also done for customer arrivals to quantify the impact of implementing the scheduling system. The findings of the research clearly indicate the feasibility and the customer service improvements derived by customer scheduling. The customer waiting times and the idling of the distribution point assets can be significantly reduced by the developed scheduling system. Customers’ perception of the waiting time can be reduced by providing waiting information of customers prior to their arrival.
- item: Conference-AbstractReview on development of natural rubber/nanoclay nanocompositesJayaraj, KS; Walpalage, S; Egodage, SMThe advantages of nanocomposites containing single silicate layers uniformly dispersed in a polymer matrix were first demonstrated by researchers at Toyota in Japan, who developed nylon-6 nanocomposites and published in 1993. Polymer-nanoclay nanocomposites have attracted the attention of many researchers thereafter due to their outstanding mechanical and barrier properties. This concept is first applied to synthesis of plastics/nanoclay nanocomposites and then expanded to preparation of ubber/nanoclay nanocomposites, since few years later. The various types of synthetic rubbers, such as silicon rubber, nitrile rubber and epoxy rubber, were used to prepare nanocomposites using different techniques, namely, melt intercalation, in situ intercalative polymerization, exfoliationadsorption and template synthesis, etc. Natural rubber (NR) was also used to prepare nanocomposites using the same techniques but with some modifications in the last decade. Now a day’s nanocomposites are widely developed in NR latex industry to achieve required properties with minimum use of clay content. NR/nanoclay nanocomposites exhibit markedly improved properties when compared to pure NR or their traditional composites. Most notable properties are increased tensile properties, gas barrier properties and heat distortion temperature, resistance to small molecule permeation, increase in atomic oxygen resistance and retention of impact strength. Tensile strength and modulus were recorded in current research as enhanced by more than two times or even ten times. It was noticed that obtaining a fully exfoliated structure is not at the desired level. Nanoclay nanocomposites are considered as fully exfoliated when inter gallery distance is greater than 10 nm but it was not achieved in many research work. Establishment of exfoliated structures in nanocomposites prepared in industrial scale is the major challenge that NR industry faces at present. NR/nanoclay nanocomposites produced with existing techniques develop high property fluctuations. Therefore, it is necessary to develop a technique to minimize property fluctuations and to obtain a reliable NR based product. It is predicted by this review that co-coagulation technique is the most promising and potential technique to fulfill the requirements of developing a NR/nanoclay nanocomposite. Use of modified nanoclays like Organoclays will aid to obtain a reliable NR based product.
- item: Conference-AbstractRepoZip : a technique for lossless compression of document collectionsSumanaweera, DN; Doole, FF; Pathiraja, DP; Deshapriya, GGK; Dias, GMany computer systems; especially in corporations, contain large amount of documents such as letters, reports and presentations. Many such documents are present in several versions. Such data needs to be synchronized with branch offices and mobile devices, often over slow and expensive connections. However, as many documents are stored in an already compressed format, it is difficult to compress them further by exploiting the hidden redundancies. We present a novel approach named RepoZip which improves the compression of an existing compression algorithm over a document collection, by exploiting the inter-document meta-data and content-level redundancies. It concentrates on compressing OOXML documents that have been constructed through the archival of a hierarchy of meta-data files and PDF documents which include deflated content streams. Therefore, the RepoZip approach achieves larger compression gains over OOXML document collections or PDF document collections by exploiting usually undetected meta-data level similarities.
- item: Conference-AbstractRegion growing segmentation method for extracting vessel structures from Coronary Cine-angiogramsKulathilake, KASH; Ranathunga, L; Constantine, GR; Abdullah, NAThe coronary cine-angiogram (CCA) is an invasive medical image modality which is used to determine the luminal obstructions or stenosis in the Coronary Arteries (CA). CCA based quantitative assessment of vascular morphology is a demanding area in medical diagnosis and segmentation of blood vessels in CCAs is one of the mandatory step in this endeavor.The accurate segmentation of CAs in Angiogram is a challenging task due to various reported reasons. In order to overcome this challenge, we proposed a region growing segmentation method which implements using morphological image processing operations and flood fill method. It can extract the boundary of main CA visualized in the processed CCA completely. The result of the proposed method reveals that this proposed segmentation method possesses 90.89% accuracy to segment the CAs related to the selected Angiography views. This segmentation results can be further enhanced to determine the functional severity of the CA and this study laid the foundation to improve the Angiography based diagnosis technique.
- item: Conference-AbstractRecommendations for successful SAP implementation in Sri Lankan business industriesThavendran, N; Perera, Mmany organizations in the world tend to implement Enterprise Resource Planning (ERP) systems to gain the full benefits of their business processes. System Application and Products (SAP) is one of most popular ERP System [18] available in the market. Most of the Sri Lankan organizations also focus on SAP implementation. Unfortunately, a large number of organizations fail to achieve their objectives due to unsuccessful implementation. This paper focuses on providing recommendations for successful SAP implementation in Sri Lankan business industries. It also focuses on implementation issues, role of vendors and consultants in SAP implementation, future trends, learning and emerging issues. Further, this paper will be extended to an in-depth study of SAP systems and its benefits. This paper will be helpful for companies in different industries which are planning to implement SAP.
- item: Conference-AbstractPotential of plug flow digesters for biogas production in the Sri Lankan domestic contextHasangika, WAS; Jaanuvi, S; Karunathilake, hp; Manthilake, MMID; Rathnasiri, PG; Sugathapala, AGTBiogas production through anaerobic digestion is widely used to convert domestic and industrial waste into energy. In order to successfully adapt this technology for Sri Lankan domestic usage, it is necessary to identify the necessary operating conditions for optimum biogas generation. This study focused on analysing the effect of co-digestion ratios and organic loading rates on processing local domestic waste. Experiments were conducted on a laboratory scale plug flow anaerobic digester setup. The best methane yield was obtained with a co-digestion ratio of garden to kitchen waste of 70:30, at an Organic Loading Rate of 3.1 kgVS/day/m3. The energy potential of the generated biogas was evaluated in comparison to the average demand of households in the country, to establish the viability of biogas substitute to conventional energy sources. Future work is needed to validate the experimental results through mathematical modelling.
- item: Conference-AbstractNumerical modelling methods of biomass combustion in packed bedsPerera, KUC; Narayana, MThe cyclic nature of biomass as a fuel, has taken its advantages over fossil fuel Biomass contributes to the largest share of the renewable energy supply of present world. For effective utilization of energy stored in biomass by combustion a good understanding of the mechanisms involved in the combustion process should be obtained. Study of the mechanisms an be done through experiments or using Computational Fluid Dynamics (CFD) method. The numerical simulation approaches related to packed bed combustion modeling retrieved from research papers, books and other publications is presented in this work. This will provide a basis for understanding the complexities in biomass combustion modeling in packed beds.
- item: Conference-AbstractNine level cascaded H bridge inverter (For High performing UPS applications)Darmawardana, PDH; Kahingala, td; Karunarathna, KMCG; Kularatne, LBSN; Karunadasa, JPThis paper proposes a nine level Cascaded H-Bridge Multi-Level Inverter, realized via Distortion Minimization PWM technology which is incorporated in an Uninterrupted Power Supply (UPS), operating in the low power end. The proposed UPS is capable of supplying four typical personal computers simultaneously. Due to the increased number of switching power poles used, switching frequency per device is reduced, minimizing the switching stress per device. Thus a prolonged lifetime of the inverter can be anticipated. Moreover, the suitability of Distortion minimization PWM for this inverter design is discussed compared to Selective Harmonic Elimination PWM (SHEPWM): one of the most popular PWM methods for multi-level inverters. Furthermore, in order to incorporate the designed inverter in a UPS application such that cost, weight and size are minimized while ensuring a good transient response at the failure of the mains supply, a novel approach named “Offline Synchronization”: an attempt to combine the advantages of both offline UPSs and Online UPSs is introduced.
- item: Conference-AbstractMulti-beam 8 × 8 RF aperture digital beamformers using mMultiplierless 2-D FFT appro ximationsKulasekera, S; Madanayake, A; Wijenayake, C; Bayer, FM; Suarez, D; Cintra, RJThe two-dimensional (2-D) discrete Fourier transform (DFT) is widely used in digital signal processing (DSP) and computing applications. Fast Fourier transforms (FFTs) are widely used as low-complexity algorithms for the computation of the DFT as it reduces the required computation operations from O(N2) to O(N log2 N). The multiplicative complexity is used as a benchmark in comparing different algorithms as it affects the circuit complexity, chip area and power. This paper introduces a new class of multiplierless hardware algorithm consisting only of arithmetic adder circuits that closely approximates the 2-D version of the 8-point DFT. The paper discusses the theory behind the proposed new algorithm, with the DFT presented in the form of an 8 × 8 matrix. Furthermore it provide a multi-beam RF aperture application example where the 2-D DFT approximation has been used to closely obtain the antenna array patterns.
- item: Conference-AbstractModification of thermal conductivity of cotton fabric using grapheneGunasekera, U; Perera, N; Perera, S; Hareendra, Y; Somaweera, L; De Silva, N; Tissera, N; Wijesinghe, RThis paper investigates the possibility to use Graphene coated fabric for thermal conductive purposes. Existing methods of thermal conductivity improvement of textiles require extrusion facilities and the end products are heavy due to insertion of metal wires. By using Graphene Oxide application, these disadvantages can be eliminated. Graphene Oxide was applied onto the fabric using a simple dip and dry method and an exhaustion dyeing method. Then the coated fabric was allowed to react with an aqueous solution of reducing agents. The test results showed that the most suitable method to obtain a significant improvement in thermal conductivity of textiles is to follow an exhaustion dyeing method with reducing agents. The reduction process should be maintained at 700C for 30min duration with the addition of Sodium Hydrosulphide. Exhaust dyed fabric which was treated with reducing agents showed an improvement of 55% in thermal conductivity compared to the uncoated fabric, which is a significant improvement in the thermal conductivity of textiles. In addition to the thermal conductivity values, few related textile properties were tested to evaluate the effect of the Graphene coating on the fabric characteristics.
- item: Conference-AbstractModeling of optical carrier recovery using four wave mixing technique for binary phase shift keying systemsMalasinghe, L; Weerasuriya, RModern communication networks uses optical fibre extensively. The transport networks are upgrading its capacity continuously to provide the bandwidth requirement of the customer requirements. To provide such an increase in bandwidth, the transmission networks are moving from Amplitude Shift Keying modulation methods to Phase Shift Keying methods. In phase shift keying systems, data reception and regeneration required phase synchronization. This requires original optical carrier phase information. In this paper, we report a model for optical carrier recovery for optical synchronization of a Binary Phase Shift Keying input by exploiting Four Wave Mixing in Highly Non-Linear Fibers. The noise influence from the signal laser for the recovered carrier was analyzed.
- item: Conference-AbstractMathematical analysis of startup mark in elastic tape on a narrow fabric loomDayaratne, HDCT; Premakumara, R; Perera, T; Prince, S; Fernando, EASK; Jayawardane, TSSStart-up marks are considered as one of the major defect in woven fabric, it occurs when the loom is restarted after loom stoppage due to various reasons. This defect is more prominent in high speed weaving looms especially with elastic warp yarns and is caused to deteriorate the fabric quality. This research paper deals with the mathematical analysis of the startup mark generation in elastic tape on narrow fabric loom. Mathematical analysis was carried out for both continuous operation condition and under stopping condition of the narrow fabric loom. A system simulation was carried out using the model developed and compared with the experimental results to show the accuracy of the model.
- item: Conference-AbstractLow Cost Fiber Optic Teaching Aid with Wide Dynamic Range Optical Power Meter and Bandwidth AnalyzerSamarawickrama, YC; Thilakumara, RPFiber optic communication technology is an essential component in any Electrical Engineering curriculum. Unfortunately the expensive fiber optic communication equipment is a major drawback in teaching fiber optics theories and principles especially in the 3rd world countries. This paper presents a development of a low cost Fiber optic power meter and a bandwidth analyzer to be used in laboratories as a teaching aid. Both power meter and analyzer are designed to operate at 850nm, 1310nm and 1550nm optical wavelengths. Analyzer measures the bandwidth of a modulated optical signal up to 500 MHz. The logarithmic amplifier enhances the power meter dynamic range. The cost of the product is less than 100 US dollars at small scale production and can be further reduced if mass produced.
- item: Conference-AbstractLow Cost Fiber Optic Teaching Aid with Wide Dynamic Range Optical Power Meter and Bandwidth AnalyzerSamarawickrama, YC; Thilakumara, RPFiber optic communication technology is an essential component in any Electrical Engineering curriculum. Unfortunately the expensive fiber optic communication equipment is a major drawback in teaching fiber optics theories and principles especially in the 3rd world countries. This paper presents a development of a low cost Fiber optic power meter and a bandwidth analyzer to be used in laboratories as a teaching aid. Both power meter and analyzer are designed to operate at 850nm, 1310nm and 1550nm optical wavelengths. Analyzer measures the bandwidth of a modulated optical signal up to 500 MHz. The logarithmic amplifier enhances the power meter dynamic range. The cost of the product is less than 100 US dollars at small scale production and can be further reduced if mass produced.
- item: Conference-AbstractIntroduction of flap gates for Anicuts in Wet ZonePieris, K; Vitharana, P; Narayana, M; Perera, KUC; Perera, SWater diversion mechanisms are commonly used in the irrigation systems and this concept is older than tank (reservoir) systems in Sri Lanka. At present, for water diversions in the wet zone anicuts are constructed by using lifting type gates. Anicuts are used to maintain required water level in the upstream by releasing only the excess water to downstream. In the lifting gate, water is allowed to flow from the bottom and this causes high erosion in the canal. The thrust force due to water pressure on the lifting gate makes it difficult to operate the system and then controlling the system is a complex task. This paper describes the construction and operation of newly introduced flap gates and issues related to lifting gate which are presently used for diversion process. In this analysis, conceptual design of a flap gate with compressive arc type wall plate is proposed to minimize use of construction materials. In the proposed system, height of the anicut could be changed from the top and then the water level in the upstream is not varied much when compared with lifting gates for varying flows in the cannel. According to the practical experiences from implemented proposed systems, controlling of the system is much easier compared to the conventional system.